Abstract: Journal bearings used in IC engines are prone to premature
failures and are likely to fail earlier than the rated life due to
highly impulsive and unstable operating conditions and frequent
starts/stops. Vibration signature extraction and wear debris analysis
techniques are prevalent in industry for condition monitoring of
rotary machinery. However, both techniques involve a great deal of
technical expertise, time, and cost. Limited literature is available on
the application of these techniques for fault detection in reciprocating
machinery, due to the complex nature of impact forces that
confounds the extraction of fault signals for vibration-based analysis
and wear prediction. In present study, a simulation model was developed to investigate
the bearing wear behaviour, resulting because of different operating
conditions, to complement the vibration analysis. In current
simulation, the dynamics of the engine was established first, based on
which the hydrodynamic journal bearing forces were evaluated by
numerical solution of the Reynold’s equation. In addition, the
essential outputs of interest in this study, critical to determine wear
rates are the tangential velocity and oil film thickness between the
journals and bearing sleeve, which if not maintained appropriately,
have a detrimental effect on the bearing performance. Archard’s wear prediction model was used in the simulation to
calculate the wear rate of bearings with specific location information
as all determinative parameters were obtained with reference to crank
rotation. Oil film thickness obtained from the model was used as a
criterion to determine if the lubrication is sufficient to prevent contact
between the journal and bearing thus causing accelerated wear. A
limiting value of 1 μm was used as the minimum oil film thickness
needed to prevent contact. The increased wear rate with growing
severity of operating conditions is analogous and comparable to the
rise in amplitude of the squared envelope of the referenced vibration
signals. Thus on one hand, the developed model demonstrated its
capability to explain wear behaviour and on the other hand it also
helps to establish a co-relation between wear based and vibration
based analysis. Therefore, the model provides a cost effective and
quick approach to predict the impending wear in IC engine bearings
under various operating conditions.
Abstract: Test automation allows performing difficult and time
consuming manual software testing tasks efficiently, quickly and
repeatedly. However, development and maintenance of automated
tests is expensive, so it needs a proper prioritization what to automate
first. This paper describes a simple yet efficient approach for such
prioritization of test cases based on the effort needed for both manual
execution and software test automation. The suggested approach is
very flexible because it allows working with a variety of assessment
methods, and adding or removing new candidates at any time. The
theoretical ideas presented in this article have been successfully
applied in real world situations in several software companies by the
authors and their colleagues including testing of real estate websites,
cryptographic and authentication solutions, OSGi-based middleware
framework that has been applied in various systems for smart homes,
connected cars, production plants, sensors, home appliances, car head
units and engine control units (ECU), vending machines, medical
devices, industry equipment and other devices that either contain or
are connected to an embedded service gateway.
Abstract: Bottom ash from Municipal Solid Waste Incineration
(MSWI) can be viewed as a typical granular material because these
industrial by-products result from the incineration of various
domestic wastes. MSWI bottom ash is mainly used in road
engineering in substitution of the traditional natural aggregates. As
the characterization of their mechanical behavior is essential in order
to use them, specific studies have been led over the past few years. In
the first part of this paper, the mechanical behavior of MSWI bottom
ash is studied with triaxial tests. After, analysis of the experiment
results, the simulation of triaxial tests is carried out by using the
software package CESAR-LCPC. As the first approach in modeling
of this new class material, the Mohr-Coulomb model was chosen to
describe the evolution of material under the influence of external
mechanical actions.
Abstract: The paper presents a method in which the expert
knowledge is applied to fuzzy inference model. Even a less
experienced person could benefit from the use of such a system, e.g.
urban planners, officials. The analysis result is obtained in a very
short time, so a large number of the proposed locations can also be
verified in a short time. The proposed method is intended for testing
of locations of car parks in a city. The paper shows selected examples
of locations of the P&R facilities in cities planning to introduce the
P&R. The analyses of existing objects are also shown in the paper
and they are confronted with the opinions of the system users, with
particular emphasis on unpopular locations. The results of the
analyses are compared to expert analysis of the P&R facilities
location that was outsourced by the city and the opinions about
existing facilities users that were expressed on social networking
sites. The obtained results are consistent with actual users’ feedback.
The proposed method proves to be good, but does not require the
involvement of a large experts team and large financial contributions
for complicated research. The method also provides an opportunity to
show the alternative location of P&R facilities. Although the results
of the method are approximate, they are not worse than results of
analysis of employed experts. The advantage of this method is ease of
use, which simplifies the professional expert analysis. The ability of
analyzing a large number of alternative locations gives a broader
view on the problem. It is valuable that the arduous analysis of the
team of people can be replaced by the model's calculation. According
to the authors, the proposed method is also suitable for
implementation on a GIS platform.
Abstract: In India, most of the pavement is laid by bituminous
road and the consumption of binder is high for pavement construction
and also modified binders are used to satisfy any specific pavement
requirement. Since the binders are visco-elastic material which is
having the mechanical properties of binder transition from viscoelastic
solid to visco-elastic fluid. In this paper, two different
protocols were used to measure the viscosity property of binder using
a Brookfield Viscometer and there is a need to find the appropriate
mixing and compaction temperatures of various types of binders
which can result in complete aggregate coating and adequate field
density of HMA mixtures. The aim of this work is to find the
transition temperature from Non-Newtonian behavior to Newtonian
behavior of the binder by adopting a steady shear protocol and the
shear rate ramp protocol. The transition from non-Newtonian to
Newtonian can occur through an increase of temperature and shear of
the material. The test has been conducted for unmodified binder VG
30. The transition temperature was found in the unmodified binder
VG is 120oC. Therefore, the application of both modified binder and
unmodified binder in the pavement construction needs to be studied
properly by considering temperature and traffic loading factors of the
respective project site.
Abstract: Cochlear Implantation (CI) which became a routine
procedure for the last decades is an electronic device that provides a
sense of sound for patients who are severely and profoundly deaf.
The optimal success of this implantation depends on the electrode
technology and deep insertion techniques. However, this manual
insertion procedure may cause mechanical trauma which can lead to
severe destruction of the delicate intracochlear structure.
Accordingly, future improvement of the cochlear electrode implant
insertion needs reduction of the excessive force application during
the cochlear implantation which causes tissue damage and trauma.
This study is examined tool-tissue interaction of large prototype scale
digit embedded with distributive tactile sensor based upon cochlear
electrode and large prototype scale cochlea phantom for simulating
the human cochlear which could lead to small scale digit
requirements. The digit, distributive tactile sensors embedded with
silicon-substrate was inserted into the cochlea phantom to measure
any digit/phantom interaction and position of the digit in order to
minimize tissue and trauma damage during the electrode cochlear
insertion. The digit have provided tactile information from the digitphantom
insertion interaction such as contact status, tip penetration,
obstacles, relative shape and location, contact orientation and
multiple contacts. The tests demonstrated that even devices of such a
relative simple design with low cost have potential to improve
cochlear implant surgery and other lumen mapping applications by
providing tactile sensory feedback information and thus controlling
the insertion through sensing and control of the tip of the implant
during the insertion. In that approach, the surgeon could minimize the
tissue damage and potential damage to the delicate structures within
the cochlear caused by current manual electrode insertion of the
cochlear implantation. This approach also can be applied to other
minimally invasive surgery applications as well as diagnosis and path
navigation procedures.
Abstract: The main objective of this research is to describe the
relationship between organizational climate and organizational
citizenship behavior. In order to examine this relationship, a research
is intended to be carried out in relevant institutions and organizations
operating in the health sector in Turkey. It will be researched that
whether there is a statistically significant relationship between
organizational climate and organizational citizenship behavior
through elated scientific research methods and statistical analysis. In
addition, relationships between the dimensions of organizational
climate and organizational citizenship behavior subscales will be
questioned statistically.
Abstract: The occurrences of precipitation, also commonly
referred as rain, in the form of "convective" and "stratiform" have
been identified to exist worldwide. In this study, the radar return
echoes or known as reflectivity values acquired from radar scans
have been exploited in the process of classifying the type of rain
endured. The investigation use radar data from Malaysian
Meteorology Department (MMD). It is possible to discriminate the
types of rain experienced in tropical region by observing the vertical
characteristics of the rain structure. .Heavy rain in tropical region
profoundly affects radiowave signals, causing transmission
interference and signal fading. Required wireless system fade margin
depends on the type of rain. Information relating to the two
mentioned types of rain is critical for the system engineers and
researchers in their endeavour to improve the reliability of
communication links. This paper highlights the quantification of
percentage occurrences over one year period in 2009.
Abstract: Genetic algorithm is widely used in optimization
problems for its excellent global search capabilities and highly parallel
processing capabilities; but, it converges prematurely and has a poor
local optimization capability in actual operation. Simulated annealing
algorithm can avoid the search process falling into local optimum. A
hybrid genetic algorithm based on simulated annealing is designed by
combining the advantages of genetic algorithm and simulated
annealing algorithm. The numerical experiment represents the hybrid
genetic algorithm can be applied to solve the function optimization
problems efficiently.
Abstract: In this paper, a linear mixed model which has two
random effects is broken up into two models. This thesis gets
the parameter estimation of the original model and an estimation’s
statistical qualities based on these two models. Then many important
properties are given by comparing this estimation with other general
estimations. At the same time, this paper proves the analysis of
variance estimate (ANOVAE) about σ2 of the original model is equal
to the least-squares estimation (LSE) about σ2 of these two models.
Finally, it also proves that this estimation is better than ANOVAE
under Stein function and special condition in some degree.
Abstract: Lightweight and efficient structures have the aim to
enhance the efficiency of the components in various industries.
Toward this end, composites are one of the most widely used
materials because of durability, high strength and modulus, and low
weight. One type of the advanced composites is grid-stiffened
composite (GSC) structures, which have been extensively considered
in aerospace, automotive, and aircraft industries. They are one of the
top candidates for replacing some of the traditional components,
which are used here. Although there are a good number of published
surveys on the design aspects and fabrication of GSC structures, little
systematic work has been reported on their material modification to
improve their properties, to our knowledge. Matrix modification
using nanoparticles is an effective method to enhance the flexural
properties of the fibrous composites. In the present study, a silanecoupling
agent (3-glycidoxypropyltrimethoxysilane/3-GPTS) was
introduced onto the silica (SiO2) nanoparticle surface and its effects
on the three-point flexural response of isogrid E-glass/epoxy
composites were assessed. Based on the Fourier Transform Infrared
Spectrometer (FTIR) spectra, it was inferred that the 3-GPTS
coupling agent was successfully grafted onto the surface of SiO2
nanoparticles after modification. Flexural test revealed an
improvement of 16%, 14%, and 36% in stiffness, maximum load and
energy absorption of the isogrid specimen filled with 3 wt.% 3-
GPTS/SiO2 compared to the neat one. It would be worth mentioning
that in these structures, considerable energy absorption was observed
after the primary failure related to the load peak. In addition, 3-
GPTMS functionalization had a positive effect on the flexural
behavior of the multiscale isogrid composites. In conclusion, this
study suggests that the addition of modified silica nanoparticles is a
promising method to improve the flexural properties of the gridstiffened
fibrous composite structures.
Abstract: In this paper, we discuss some properties of left
spectrum and give the representation of linear preserver map the left
spectrum of diagonal quaternionic matrices.
Abstract: Information technology has been gaining more and
more space whether in industry, commerce or even for personal use,
but the misuse of it brings harm to the environment and human health
as a result. Contribute to the sustainability of the planet is to
compensate the environment, all or part of what withdraws it. The
green computing also came to propose practical for use in IT in an
environmentally correct way in aid of strategic management and
communication. This work focuses on showing how a mobile
application can help businesses reduce costs and reduced
environmental impacts caused by its processes, through a case study
of a public company in Brazil.
Abstract: Polymeric composites are being increasingly used as
repair material for repairing critical infrastructures such as building,
bridge, pressure vessel, piping and pipeline. Technique in repairing
damaged pipes is one of the major concerns of pipeline owners.
Considerable researches have been carried out on the repair of
corroded pipes using composite materials. This article attempts a
short review of the subject matter to provide insight into various
techniques used in repairing corroded pipes, focusing on a wide range
of composite repair systems. These systems including pre-cured
layered, flexible wet lay-up, pre-impregnated, split composite sleeve
and flexible tape systems. Both advantages and limitations of these
repair systems were highlighted. Critical technical aspects have been
discussed through the current standards and practices. Research gaps
and future study scopes in achieving more effective design
philosophy are also presented.
Abstract: Issues relating to the destructive phenomena that can
damage people and goods have returned to the centre of debate in
Italy with the increase in catastrophic episodes in recent years in a
country which is highly vulnerable to hydrological risk.
Environmental factors and geological and geomorphological
territorial characteristics play an important role in determining the
level of vulnerability and the natural tendency to risk. However, a
territory has also been subjected to the requirements of and
transformations of society and this brings other relevant factors. The
reasons for the increase in destructive phenomena are often to be
found in the territorial development models adopted. Stewardship of
the landscape and management of risk are related issues. This study aims to summarize the most relevant elements about
this connection and at the same time to clarify the role of
environmental risk assessment as a tool to aid in the sustainable
management of landscape. Finally, the study reflects on how regional
and urban planners deal with environmental risk and which aspects
should be monitored in order to adopt responsible and useful
interventions.
Abstract: The aim of this work is to study the numerical
implementation of the Hilbert Uniqueness Method for the exact
boundary controllability of Euler-Bernoulli beam equation. This study
may be difficult. This will depend on the problem under consideration
(geometry, control and dimension) and the numerical method used.
Knowledge of the asymptotic behaviour of the control governing the
system at time T may be useful for its calculation. This idea will
be developed in this study. We have characterized as a first step, the
solution by a minimization principle and proposed secondly a method
for its resolution to approximate the control steering the considered
system to rest at time T.
Abstract: Contemporary metropolitan areas and large cities are
dynamic, rapidly growing and continuously changing. Thus, urban
transformations and mutations are not a new phenomenon, but rather
a continuous process. Basic factors of urban transformation are
related to development of technologies, globalisation, lifestyle, etc.,
which in combination with local factors have generated an extremely
great variety of urban development conditions. This article discusses
the main urbanisation processes in Lithuania during last 50-year
period and social factors affecting urban functional mutations.
Abstract: The purpose of this study is to analyze the temporal
and spatial variability of thermal conditions in the Republic of
Armenia. The paper describes annual fluctuations in air temperature.
Research has been focused on case study region of Armenia and
surrounding areas, where long–term measurements and observations
of weather conditions have been performed within the National
Meteorological Service of Armenia and its surrounding areas. The
study contains yearly air temperature data recorded between 1961-
2012. Mann-Kendal test and the autocorrelation function were
applied to detect the change trend of annual mean temperature, as
well as other parametric and non-parametric tests searching to find
the presence of some breaks in the long term evolution of
temperature. The analysis of all records reveals a tendency mostly
towards warmer years, with increased temperatures especially in
valleys and inner basins. The maximum temperature increase is up to
1,5°C. Negative results have not been observed in Armenia. The
patterns of temperature change have been observed since the 1990’s
over much of the Armenian territory. The climate in Armenia was
influenced by global change in the last 2 decades, as results from the
methods employed within the study.
Abstract: In the present work, forming limit diagrams and strain
distribution profile diagrams for extra deep drawing steel at room and
elevated temperatures have been determined experimentally by
conducting stretch forming experiments by using designed and
fabricated warm stretchforming tooling setup. With the help of
forming Limit Diagrams (FLDs) and strain, distribution profile
diagrams the formability of Extra Deep Drawing steel has been
analyzed and co-related with mechanical properties like strain
hardening COEFFICIENT (n) and normal anisotropy (r−). Mechanical
properties of EDD steel from room temperature to 4500C were
determined and discussed the impact of temperature on the properties
like work hardening exponent (n) anisotropy (r-) and strength
coefficient of the material. In addition, the fractured surfaces after
stretching have undergone the some metallurgical investigations and
attempt has been made to co-relate with the formability of EDD steel
sheets. They are co-related and good agreement with FLDs at various
temperatures.
Abstract: Fluctuations of Schottky diode parameters in a
structure of the mixer are investigated. These fluctuations are
manifested in two ways. At the first, they lead to fluctuations in the
transfer factor that is lead to the amplitude fluctuations in the signal
of intermediate frequency. On the basis of the measurement data of
1/f noise of the diode at forward current, the estimation of a spectrum
of relative fluctuations in transfer factor of the mixer is executed.
Current dependence of the spectrum of relative fluctuations in
transfer factor of the mixer and dependence of the spectrum of
relative fluctuations in transfer factor of the mixer on the amplitude
of the heterodyne signal are investigated. At the second, fluctuations
in parameters of the diode lead to occurrence of 1/f noise in the
output signal of the mixer. This noise limits the sensitivity of the
mixer to the value of received signal.